Record-high numbers of migrants have attempted to cross into the US border. Data on these border encounters, which refers to unauthorized or denied entries into the country, plays an important role in helping the government estimate the number of individuals illegally entering the US.
By understanding the demographics and origins of people encountered at the border, policymakers can gain a clearer understand of the complex factors driving immigration and shape informed policy decisions.
The Department of Homeland Security separates border encounters into three categories:
These encounters do not necessarily correspond to the number of people attempting to cross the border since the people can make multiple attempts to cross the border within the same fiscal year.
Also, a single border encounter can encompass groups of different sizes, ranging from entire families or single individuals, and still register as only a single incident, meaning the term “encounters” should not be conflated with “people.”
Undocumented immigrants, sometimes called illegal aliens, are foreign-born individuals who lack a valid visa or other necessary immigration documentation due to entering the U.S. without inspection, exceeding the allowed duration of their temporary visa, or breaching the terms of their admission.
On the other hand, documented, or legal, immigrants are individuals born in foreign countries who have attained legal status to enter and live in the United States.
Between October 2019 and June 2023, the US Customs and Border Protection (CBP) office reported almost 7.7 million border encounters across the US. Monthly encounters peaked at over 300,000 people in December 2022.
For comparison, average annual apprehensions rose from approximately 394,000 between fiscal years 2010 and 2018 to 658,315 between fiscal years 2020 and 2022.
Border encounters dropped slightly between March and April 2020. During this time, former President Donald Trump’s administration invoked Title 42 to authorize border expulsions in the interest of public health during the pandemic.
The Title 42 public health order ended in May 2023, meaning border patrol officers could no longer expel illegal migrants for COVID-19-related reasons.
Although the pandemic initially appeared to lower border encounters, they gradually rebounded over 2020. Notably, these encounters surged by 66% between February and March 2021, and have since remained at an elevated level.
While there isn’t any definitive data on the inflow of undocumented immigrants, border encounters serve as a helpful, if imperfect, proxy. This data helps the Office of Immigration Statistics model what proportion of illegal entries are prevented by apprehensions, captured by the at-the-border apprehension rate.
Despite the relatively high number of encounters in 2021, the CBP’s improved estimated at-the-border apprehension rate averaged 78% from 2018 to 2020, compared to 35% from 2002 to 2004. This resulted in fewer entries without inspection than in the early 2000s.
According to preliminary estimates at the time, approximately 660,000 people crossing the border evaded apprehension in fiscal year 2021. While this was an increase compared to seen from 2014 to 2020 (160,000 per year), it was still lower than any year from 2000 to 2010 and only one-third as high as estimates for 2000 to 2006.
According to the CBP, roughly 80% of people apprehended or denied entry between October 2019 and June 2023 were Latin American citizens. More than 30% came from Mexico, followed by Honduras (9.2%), Guatemala (9.0%), Venezuela (5.8%), and Cuba (5.8%).
Border encounters have risen for all nations monitored by the CBP since 2019. However, the numbers can vary over time based on each country’s unique political and economics dynamics, travel distances, and factors influencing migration patterns.
While illegal border encounters occur all over the country, including non-border states, 82.8% of cases between October 2019 and June 2023 occurred along the US-Mexico border.
Texas had 49.6% of nationwide border encounters within its territory, followed by Arizona at 17.9%, and California at 14.0%.
Within this period, over 70% of the people the CBP encountered were single adults. The proportion of encounters with whole family units (categorized as FMUA) doubled between fiscal years 2020 and 2021 from 11.6% to 24.7% of total cases.
All data included in this article comes from US Customs and Border Protection’s data on nationwide encounters.
Nationwide encounters include the sum of CBP encounters across all areas of responsibility. This includes the northern land border, the southwest land border, the OFO non-land border ports of entry (such as airports and seaports), and the USBP sectors that do not share a land border (such as Florida or New York).
According to an August 2020 CBP report, the Department of Homeland Security estimates unauthorized border crossings by collecting data from various sources, including border encounters and refugee and asylee figures, as well as migrant sample surveys, interviews, and other statistical methodologies.
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